This invention relates to a jigsaw, and, more particularly, to a jigsaw including a blade retention system which permits the blade of the saw to be changed without the use of any tool external to the structure of the jigsaw itself.
In known jigsaw structures, the blade is fixed to the reciprocating drive shaft either by means of fixing screws that engage lateral surfaces of the blade to clamp the blade in position as shown, for example, in U.S.-A-3665983, or by means of a combined bayonet and fixing screw system, as shown in G.B.-A-1173172, in which the blade is provided with bayonet lugs which are held, in use, in corresponding retention grooves provided in an end cap of the drive shaft by a screw which engages the end of the blade.
Both of these systems have the disadvantage of requiring the use of an external tool (a screwdriver) in order to change the blade. Not only is this inconvenient, but also there is the danger that an inexperienced or careless operator may either damage a retaining screw in the process of changing a blade, or may inadequately tighten a fixing screw with the result that the blade may inadvertently be released from the drive shaft in use.